Background Information The Phase II of the contract has four objectives: Objective #1: Scale-up and analytical characterization of the lead radiotherapeutic agent selected from Phase I. Objective #2: Optimization of dose/regimen in an animal efficacy model using a PSMA-expressing subcutaneous human prostate tumor. Objective #3: Maximum Tolerate Dose Study of Lead 177Lu-DOTA-PSMA therapeutic agent in normal male rats. Objective #4: Assess safety of the radiolabeled lead agent in an IND-enabling GLP study in adult male rats. Three of these objectives will be pursued by the Subcontractors at University of Pittsburgh.